Method and apparatus for thermally upgrading carbonaceous materials

ABSTRACT

Carbonaceous materials are thermally upgraded in a pressurized steam environment to remove moisture and other byproducts. A variety of water/solid separation devices may be employed in a process vessel to maximize moisture removal from the upgraded charge. Heating media inlet nozzles and process chamber vents are strategically positioned at the process vessel wall to minimize short circuiting of heating media to vessel outlet vents and to continuously separate hot water removed from the charge and condensed steam, such that the upgraded material removed from the process vessel is not discharged with accompanying free moisture. After upgrading, the charge may be rehydrated to improve its stability during shipping and storage.

BACKGROUND OF THE INVENTION

The invention generally relates to thermal upgrading of carbonaceousmaterials, such as sub-bituminous rank and lignite rank coals, peat andvarious forms of bio-mass fuels. More particularly, the inventionconcerns thermal upgrading of carbonaceous materials by direct contactwith a heating medium and by removing moisture from the charge as hotwater.

U.S. Pat. No. 5,071,447 to Koppelman discloses methods and apparatus forsteam treating carbonaceous materials. Under the system disclosed in the'447 patent, steam is injected at the top of a processing vessel.

U.S. Pat. No. 5,769,908 to Koppelman relates to the treatment ofcarbonaceous materials by injecting an inert gas into the carbonaceousmaterial under a vacuum or injecting steam into the carbonaceousmaterial either with or without the vacuum being applied in a controlledmanner to more consistently treat the charge of carbonaceous material.

While the prior teachings in the two above cited Koppelman patents arebelieved to have been advances in the art addressing many problems inthe area of thermal upgrading of materials, such as coal, there remainsa need in the art to more consistently insure that all surfaces of thecharge of carbonaceous material reach the same final temperature, tominimize free moisture accompanying the upgraded charge, and toaccomplish improved removal of unwanted byproducts from the charge.

SUMMARY OF THE INVENTION

Accordingly, apparatus for upgrading energy content of a charge ofcarbonaceous material includes a process vessel having a chamber forreceipt of the charge, a vessel inlet for transferring the charge to thechamber and a vessel outlet for transferring an upgraded charge out ofthe chamber. At least one heating medium inlet adapted to be coupled toa source of heating medium for transferring the heating medium underpressure into the process vessel chamber for direct contact with thecharge is positioned on the process vessel. At least one fluid outletcoupled in fluid communication with the process vessel chamber and atleast one liquid separator having a liquid outlet coupled to the atleast one fluid outlet and operative to separate the charge from liquidis additionally provided.

In another aspect of the invention, apparatus for upgrading energycontent of a charge of carbonaceous material utilizes a substantiallyvertically oriented process vessel having a vessel inlet positioned at atop end of the vessel, a vessel outlet positioned at a bottom end of thevessel and a chamber for receipt of the charge extending from the vesselinlet to the vessel outlet. A plurality of heating medium inlets areadapted to be coupled to a source of heating medium for transferring theheating medium under pressure into the process vessel chamber for directcontact with the charge, the heating medium inlets positioned atpreselected locations between the top end and the bottom end of thevessel. A plurality of liquid outlets are coupled in fluid communicationwith the process vessel chamber and are positioned at preselectedlocations between the top end and the bottom end of the vessel. Aplurality of process vessel vents are positioned at preselectedlocations between the top end and the bottom end of the vessel andenable selective discharge of gases from the process vessel chamber.Finally, a plurality of liquid separators are positioned at a pluralityof preselected locations within the chamber, each liquid separatorhaving a liquid collection chamber coupled to at least one of theplurality of liquid outlets and operative to separate the charge fromthe liquid.

In yet another aspect of the invention, a method for upgrading energycontent of a charge of carbonaceous material having a first equilibriummoisture level begins with directly contacting the charge with a heatingmedium under pressure to heat the charge to drive moisture from thecharge to a second moisture level below the first equilibrium moisturelevel and to lower an equilibrium moisture level of the charge to avalue between the first equilibrium moisture level and the secondmoisture level. Moisture driven from the charge is separated therefrom.

BRIEF DESCRIPTION OF THE DRAWINGS

The objects and features of the invention will become apparent from areading of a detailed description, taken in conjunction with thedrawings, in which:

FIG. 1 is a side elevation view showing the vertical orientation of afeed lock hopper on top of the main process vessel with a productdischarge lock hopper under the process vessel, in accordance with theprinciples of the present invention;

FIG. 2 is a side elevation view showing two feed lock hoppers and twoproduct discharge lock hoppers in combination with the process vesselfor providing continuous charge processing in accordance with theprinciples of the invention;

FIG. 3 is a partial cross-sectional view of the process vessel of FIG. 1showing inlet and outlet nozzle arrangements in accordance with theprinciples of the invention;

FIG. 4A is a cross-sectional view of the process vessel of FIG. 1showing inlet and outlet nozzle details in addition to solid/waterseparation devices arranged in accordance with the principles of theinvention;

FIG. 4B is an enlarged view of perforated regions of the separationsurfaces of the devices of FIG. 4A;

FIGS. 4C, D and E are top plan views of the vessel of FIG. 4A takenrespectively at locations A-A, B-B and C-C of FIG. 4A; and

FIG. 5 is a schematic showing the orientation and placement of typicalrehydration equipment and associated input, internal and output flowstreams, arranged in accordance with the principles of the invention.

DETAILED DESCRIPTION

Referring to FIG. 1, processing system 100 includes a feed lock hopper102 positioned at a top portion 104 of a process vessel 106, with adischarge lock hopper 108 positioned below a bottom portion 110 ofprocess vessel 106. At an input of each lock hopper 102 and 108 arevalves 112 and 116, respectively, which seal their respective lockhopper from atmospheric pressure up to an operating pressure of processvessel 106. Likewise, there are output valves 114 and 118 at an outputof respective lock hoppers 102, 108 which serve the same purpose.

Carbonaceous charge material in conduit 150 is intermittently fed intofeed lock hopper 102 via valve 112 being in an open position and bottomvalve 114 in a closed position. Input valve 112 is then closed, and lockhopper 102 is brought up to the same operating pressure as in processvessel 106. Valve 114 is then opened, and the charge material flows bygravity into the process vessel 106. When feed lock hopper 102 is empty,output valve 114 is closed, and the pressure in lock hopper 102 islowered to atmospheric conditions. Input valve 112 is then opened, andthe feed lock hopper 102 is ready to start another feed cycle viaconduit 150. The hourly feed rate of carbonaceous material, on anaverage basis, is determined by the weight of material fed each cycleand the number of cycles per hour, and the feed flow into the processvessel 106 is thus intermittent.

With continued reference to FIG. 1, in a manner similar to operation offeed lock hopper 102, discharge lock hopper 108 intermittently removesupgraded charge material from process vessel 106 via conduit 152. Thesimplified sequence of the cyclic operational steps would be that theempty discharge lock hopper 108 has just discharged upgraded material toatmospheric conditions and to further processing equipment via conduit152. Output valve 118 is then closed, the pressure is equalized to thatof process vessel 106, and output valve 116 is opened. After dischargelock hopper 108 is full, input valve 116 is closed and the pressure inthe lock hopper 108 is lowered to atmospheric conditions. Outlet valve118 is then opened, and output lock hopper 108 intermittently dischargesupgraded charge material via conduit 152 to complete the cycle. Thelowering of pressure in lock hopper 108 also serves to lower thetemperature through evaporation of water from inner portions of thecarbonaceous charge.

Process vessel 106 could be operated in a batch mode without using feedor discharge lock hoppers 102 or 108. An input valve 114 and an outputvalve 116 would be required, and then the sequence of operation would bethe same as for one of the lock hoppers previously described—i.e., withthe output valve 116 closed and process vessel at atmospheric pressure,feed material flows into process vessel 106 via open input valve 114.Valve 114 is then closed after the process vessel 106 is full, processvessel 106 is brought to operating pressure and temperature and, after adesired processing time, process vessel 106 pressure is lowered toatmospheric, output valve 116 is opened and the upgraded charge isdischarged. After process vessel is empty, output valve 116 is closedand the batch cycle starts again. Using multiple batch process vessels,and with the proper sequencing of cycles on each vessel, it is possibleto operate batch vessels in a manner that overall feed and discharge toand from the multiple vessels approaches continuous operation.

Using two feed lock hoppers and two discharge lock hoppers, it ispossible to achieve true continuous feed and discharge into and out ofprocess vessel 106. FIG. 2 shows an equipment arrangement that wouldallow such a continuous process. Feed charge material is fed from inletduct 252 through a diverter valve 202 which directs the feed flow toeither of the feed lock hoppers 204 or 206. For continuous feed, one ofthese lock hoppers is full and ready to feed process vessel 106 beforethe other hopper is empty. At the discharge end of the vessel, one ofthe discharge lock hoppers 208, 210 is empty and ready to receiveupgraded material before the other discharge lock hopper is full. Withthis operation the feed into process vessel 106 is continuous, and thedischarge out of process vessel 106 is continuous. Hence, process vessel106 operates in a completely continuous mode. However, because of therequirement that one of the feed lock hoppers is full and waiting tofeed and one of the discharge lock hoppers is empty and waiting toreceive discharge, the feed into the feed lock hoppers and the dischargeout of the discharge lock hoppers will not be continuous, but willapproach continuous operation.

With continued reference to FIG. 2 the sequence for continuous operationof process vessel 106 is as follows. Feed lock hopper 204 will befeeding process vessel 106 with input valve 212 in the closed positionand output valve 214 in the open position. The other feed lock hopper206 will be sitting full of feed and will be at process vessel pressure.Additionally, both input valve 216 and output valve 218 will be closed.As soon as feed lock hopper 204 is empty, output valve 214 closes andsimultaneously output valve 218 on feed lock hopper 206 opens and feedsinto the process vessel 106 in a continuous and uninterrupted manner.The pressure in feed lock hopper 204 is then lowered to atmospheric,input valve 212 is opened, diverter valve 202 is positioned to feed thecharge material into feed lock hopper 204, and the feed continues untilfeed lock hopper 204 is full. The flow of feed charge material isstopped, input valve 212 on feed lock hopper 204 is closed, the pressurein feed lock hopper 204 is equalized to process vessel 106 pressure, andthe feed lock hopper 204 then sits and waits for feed lock hopper 206 toempty. The cycle is then ready to repeat.

Still referring to FIG. 2, the sequence for operation of discharge lockhoppers 208 and 210 is the same as for feed lock hoppers 204 and 206described above, except that one of the discharge lock hoppers 208 (or210) has to be sitting empty at process vessel pressure with input valve220 open and bottom valve 222 closed, while the other discharge lockhopper 210 (or 208) is filling. When discharge lock hopper 210 is full,diverter valve 224 directs process vessel discharge into discharge lockhopper 208. Input valve 226 on discharge lock hopper 210 is closed, thepressure in the discharge lock hopper 210 is lowered to atmospheric, theoutput valve 228 on discharge lock hopper 210 is opened, and upgradedcharge is discharged to any necessary collection and conveying equipmentvia outlet duct 250. When empty, output valve 228 on discharge lockhopper 210 is closed, pressure inside the discharge lock hopper 210 isequalized with that of the process vessel 106, and input valve 226 isthen opened. Discharge lock hopper 210 then sits empty and pressurizeduntil companion discharge lock hopper 208 is full. The cycle thenrepeats.

FIG. 3 shows more detail for a single feed lock hopper operation in asemi-continuous system. Input and output valves 112 and 114 operate onfeed lock hopper 102 as described above. A pressurization inlet 302 anddepressurization outlet 304 are used to control the pressure in feedlock hopper 102. After feed lock hopper 102 has emptied its charge intoprocess vessel 106, input valve 112 is still closed, output valve 114 isstill closed, but feed lock hopper 102 is still at process vesselpressure and contains a saturated steam environment. A valve on thedepressurization outlet 304 is opened, and the saturated steam vaporflows out of the feed lock hopper 102 until atmospheric pressure isachieved and the valve on the depressurization outlet 304 is closed.Input valve 112 on feed lock hopper 102 is then opened, and the lockhopper is filled with charge material. When full, input valve 112 isclosed, and a valve on pressurization inlet 302 is opened. A suitablepressurization medium, such as saturated steam, super heated steam, airor another gas is used to raised the internal pressure to match that ofprocess vessel 106, and the valve on pressurization inlet 302 is closed.Output valve 114 on feed lock hopper 102 is then opened, and material isfed into the process vessel 106.

Non-condensable gases are continuously vented from process vessel 106using vents 306, 308 and 310 shown in FIG. 3. Non-condensable gas arisesfrom volatile organics released from the carbonaceous charge materialduring upgrading, from air that enters the upgrading process absorbed inthe feed charge material, and from any other gas introduced into theupgrading process. Non-condensable gas is normally present at minorconcentrations in process vessel 106, with a majority volume constituentbeing saturated steam vapor. Thus, when non-condensable gases arevented, there is an accompanying steam flow that represents considerableenergy loss from the upgrading process. Some of this energy can berecovered and reused by using all, or a portion, of process vessel ventflows as the pressurization gas for both feed lock hopper 102 anddischarge lock hopper 108 operation. The pressurization outlets 304 and312 on feed and discharge lock hoppers 102 and 108, respectively, ventgas that could be essentially almost pure saturated steam from theprocess. This also comprises energy loss. Using vent flows from processvessel 106 for lock hopper pressurization does not result in anyadditional energy loss from the upgrading process when vented a secondtime from lock hopper depressurization outlets 304 and 312.

With continued reference to FIG. 3, the heating medium is normallyintroduced into process vessel 106 through inlets 314 and 316 located onone side of process vessel 106, while process vessel vents 306, 308 and310 are on an opposite side of the vessel 106. Both the inlets and ventscan be at multiple elevational positions on the vessel and may involvemany more locations than shown in FIG. 3. The vents are normallyprotected by associated diverter shields 318 a, b, c which prohibitwater and solids from escaping in the vent streams, but allownon-condensable gas and steam vapor to escape. One requirement of theinlet and vent placement is to prevent short circuiting of inlet flowsdirectly to the vents. Another requirement of the inlet and ventplacement is to create flow patterns across an interior volume ofprocess vessel 106 in a substantially horizontal direction, adown-flowing direction, or an up-flowing direction to effectivelycontrol and remove non-condensable gases from process vessel 106. Forinstance, heavy non-condensable gases, such as carbon monoxide, willtend to migrate to the bottom interior portion 320 of process vessel106, and they would not effectively be removed if all of the inlet andvent flow was at the top interior portion 322 of process vessel 106. Insuch a case, inlet and vent flows would be controlled to sweep theheavier non-condensable gas out of a lower vent location. In an oppositecase, light non-condensable gas such as hydrogen will migrate to the topportion 322 of process vessel 106, and appropriate flow patterns betweenthe inlet and vent locations need to be established to controlconcentration of light non-condensable gas in a top portion 322 ofprocess vessel 106. In some instances, controlling both concentrationsof heavy and light non-condensable gases is effectively implemented withsubstantially horizontal flow patterns between process vessel 106 inletsand vent locations.

In normal operation, the heating medium flow into process vessel 106 iscontrolled by pressure in process vessel 106. If the pressure dropsbelow a desired operating set point, heating media inlet 314 flow willincrease to compensate. Conversely, if the pressure rises above thedesired operating set point, inlet flow will decrease. Vent flow out ofprocess vessel 106 is normally controlled by measuring non-condensablegas concentration in process vessel 106 and then adjusting anappropriate control valve to achieve the desired mass flow ofnon-condensable gas (and accompanying water vapor) out of process vessel106 at each desired vent location. Vent flow out of process vessel 106can be a significant variable in terms of impacting heating medium inletflow. Most of the heating medium inlet flow will be to provide sensibleheat to heat the feed charge to operating conditions, provide energy forheat losses from the process, and provide energy for heat of reactionrequirements that occur in the thermal upgrading process.

The preferred heating medium is either saturated steam or super heatedsteam introduced to the process vessel 106 through the upper and lowerheating medium inlets 314 and 316, respectively, or through any otherinlets located on an exterior wall of vessel 106. Likewise, the heatingmedium could be directed through internal piping into interior 322 ofvessel 106 and used to provide energy to selected locations.

Compressed hot water may also be used as part of the heating media. Forinstance, when relatively cold incoming charge material is fed into thetop of process vessel 106 through feed lock hopper 102, saturated steamwill immediately start to condense and transfer energy into the coldcharge thermodynamically by latent heat of condensation. The hotcondensate, or compressed hot water, at this location or other locationswithin process vessel 106, will be hotter than the charge material andwill also transfer heat into the charge material. If a suitable sourceof compressed hot water is available external to process vessel 106 atthermodynamic conditions capable of supplying heat into the thermalupgrading process, such compressed hot water could be introduced atmultiple locations and used as the entire energy supply to the process.Alternatively, compressed hot water could be used as a partialsupplement to saturated or super heated steam heating media. One benefitthat comes from using saturated steam, or super heated steam after ithas been de-super heated, is that saturated steam condensesisothermally, which means that steam will flow on its own to anylocation within process vessel 106 that is colder than the temperatureof the saturated steam, provided that the porosity of the bed of chargematerial is sufficient to allow passage of the steam vapor to the coolerareas of the bed. Until it is de-super heated, super heated steam flowmust be directed to its point of use.

It may be particularly advantageous to supply super heated steam to thethermal upgrading process through heating medium inlet 316 located nearthe bottom of process vessel 106 to serve at least two specificpurposes. One would be to initially provide thermal energy to the chargematerial in a “dry” form through loss of heat from the super heatedvapor or hot gas. This could be used to remove excess free surfacemoisture from the charge material and provide additional dewatering byconverting free moisture to saturated steam. The use of “dry” superheated steam near the bottom of the process vessel would also provide a“dry” environment around the charge material and provide a differentialin partial pressure between inherent moisture still contained in thecharge material and the relatively dry vapor space at an outer surfaceof the charge material solid particles that would provide a thermaldynamic driving force for liberation of additional inherent moisturewithin the charge.

Pressurization of discharge lock hopper 108 through pressurization inlet324, and depressurization through depressurization outlet 312 will beachieved and controlled in exactly the same manner as described abovefor feed lock hopper 102. As previously described, vent gas from vents306, 308 and 310 may be used as the pressurization gas for dischargelock hopper 108.

During upgrading of the charge, the processing vessel uses temperaturesranging from a minimum temperature where the structure of the charge'sparticles become elastic and a maximum temperature where any substantialpyrolysis occurs. Preferably, the range is 400° F. to 500° F. withcorresponding pressures of 247 psia to 680 psia, or pressures thatsubstantially match the temperature at saturated steam conditions. Dueto the presence of some amount of non-condensable gases that may bepresent in the vessel environment, the actual temperature at any giventotal process vessel pressure may be somewhat less than predicted bysaturated steam conditions. For example, if total process vesselpressure is 500 psia and the concentration of non-condensable gases is10% by volume, the partial pressure of the non-condensable gas will be50 psia and the partial pressure of the saturated steam will be 450psia. Hence the temperature of both the non-condensable gas and thesaturated steam will be about 456° F. compared to a temperature of about467° F. if only saturated steam were present.

In order for steam vapor to flow uniformly to colder regions of theprocess vessel bed for isothermally condensing and to also promotebetter draining and separation of moisture from the upgraded charge, itis desirable to use a properly sized carbonaceous feed material so thatporosity is maintained in the bed. This is achieved by crushing andscreening oversize material so that a maximum size of feed material isobtained. Likewise, some fines need to be removed from the feed materialso that the fines do not pack into the void spaces between the largerparticles and create regions of low bed porosity within the processvessel. It is recognized that because of mass to volume relationships, agiven weight of fine material will have a much larger surface area thanan equivalent weight of coarser material. Increasing the surface area ofthe charge material, also increases the area for free surface moistureto accumulate and makes dewatering of the upgraded charge moredifficult. Particle size distributions for the feed material can rangefrom 0.00 inch by minus 4 inch as an extreme, with plus 0.125 inch byminus 3 inch being more desirable, and with plus 0.25 inch by minus 2inch being most desirable. In order for these size ranges to beeffective, the feed charge material should be sized so that thedistribution of sizes within the upper and lower size limits shouldclosely follow the Rosin-Rammler index typically characteristic for thetype of charge being upgraded.

Once in process vessel 106, the carbonaceous charge is heated tooperating temperature and pressure. The average retention time of thecharge in the process vessel 106 is determined by the volume of theprocess vessel 106, the bulk density of the charge material and theweight of the material fed. Retention times between about 5 minutes andabout 1000 minutes are believed useful, with retention for about 15-60minutes more preferable and about 20-30 minutes most preferable.

In a similar manner, the presence of super-heated steam can increase thetemperature in the process vessel above that predicted by saturatedsteam conditions. Using the above example, if super-heated steam werepresent in the vessel with about 11° F. of super heat in the vapor, thenthe steam partial pressure would still be 450 psia, but the temperatureof both the steam and the non-condensable gas would increase to 467° F.,or the temperature of pure saturated steam at 500 psia.

Within the temperature and pressure ranges on a weight basis statedabove, much more energy can be released from saturated steam when itcondenses compared to energy released when super-heated steam cools downto saturated conditions or when compressed water left after condensationcools down and transfers heat. Hence, the use of saturated steam and theheat released when it isothermally condenses is the preferred approachof supplying heat to the process vessel.

As the charge reaches a desired temperature in the process vessel, thecharge becomes more elastic allowing for the release of water with aminimum amount of charge particle fracturing.

Moisture present in the charge material is removed in accordance withthe invention by several mechanisms.

The first mechanism for moisture removal is volumetric expansion ofentrained water as the charge is heated up by the surroundingenvironment. The water thermally expands at a rate faster than thecharge pore structure surrounding the water, and the water has no placeto go except to exit the charge.

A second mechanism squeezes additional water out of the charge pores asthe pores collapse in volume. The pores collapse in volume due to waterbeing removed and due to the external pressure applied on the surface ofthe charge from the processing environment.

A third mechanism involves differential pressure between moisture andvapor form trapped in the charge which escapes to a region of lowerpressure in the process vessel vapor phase.

A fourth, less desirable mechanism is removal of ionic and charge bondedwater which is accomplished through thermal dynamic equilibrium shiftsas the processing temperature increases. Removal of water from thecharge via this mechanism is preferably minimized by limiting themaximum temperature in the processing environment. If only water wereremoved by the equilibrium shift, this would be acceptable. However, atthe elevated temperatures, volatile organics contained in thecarbonaceous charge are also released. As the processing temperaturegoes up, the amount of volatiles released starts to go up at anincreased rate. The volatiles released from the charge either combinewith the water in a soluble or entrained form or mix with the steamvapor as non-condensable gases. Neither process is desirable, asorganics mixed into or soluble in the water add to the cost of watertreatment prior to reuse and/or disposal of the water and increase theconcentration of non-condensable gas in the process vessel vapor phase.

Indirect heating can also be utilized with the invention. As an example,heat exchange tubes 350 (FIG. 3) could optionally be placed anywhere inthe process vessel where there would be contact between the chargematerial and the indirect heating surface of tube 350. As long as theindirect surface is at a higher temperature than the charge, there willbe heat transferred into the charge. This may be particularlyadvantageous at a bottom of the process vessel as shown in FIG. 3 wherean indirect heat surface serves to evaporate excess surface moisturefrom the charge prior to discharge. A source of indirect heating medium(not shown) would be coupled to element(s) 350 via ports 352 and 354.

High moisture content carbonaceous materials, such as sub-bituminouscoal, contain up to 30% by weight inherent or entrained moisture. Asmined, the inherent moisture content is very close to the equilibriummoisture content of the material, which is generally defined as thatmoisture level to which the coal will re-equilibrate if exposed to a newenvironment and then re-exposed to its original environment, unless thematerial has been either structurally and/or chemically altered whenexposed to the new environment. As an example, coal mined from the seamat 30% moisture and allowed to air dry in a low humidity environment to,for example, 20% inherent moisture, will still have an equilibriummoisture value of about 30% and will eventually return or re-equilibrateto about 30% inherent moisture if exposed to a high humidity environmentover time.

Most normal upgrading processes attempt to lower the inherent moisturelevel of the charge to a level much below the equilibrium moisture levelreached during such processing. When shipped and stored, such materialwill attempt to equilibrate to its equilibrium moisture level byabsorbing moisture from the environment. If this absorption occurs toorapidly, the charge may overheat and even undergo spontaneous combustionin storage or in transit.

It is believed that careful control of the processing conditionsrelative to the charge material that is to be upgraded in accordancewith this invention will result in production of a thermally upgradedproduct that is stable and safe to ship as produced. However, withsub-bituminous charge material containing 20 to 30% inherent moisture,the resultant upgraded product in accordance with this invention willhave an equilibrium moisture level between about 8 and about 16% byweight. Based on experience, coal with an inherent moisture level ofabout 7% cannot be safely shipped and stored as is, if the equilibriummoisture level is much higher, for example at 15%. Depending on thecharge, if it is rehydrated back up to 10 to 14% inherent moisture itcan be safely shipped and stored. Rehydration may be achieved in acontrolled environment where moisture originally removed from the coalis added back to the coal or high moisture, non-upgraded or partiallyupgraded coal is blended with the low moisture upgraded charge.

Injection of air or other gas containing reactive oxygen into theprocess vessel is desirable for a number of reasons, each making use ofdesirable, highly exothermic reactions between oxygen and some form offuel in the charge or process vessel. With oxygen injection, at least aportion of organic based volatiles expelled from the upgraded charge maybe oxidized. Excess surface moisture can be burned off. Additionally, itis believed that unwanted byproducts such as mercury, can be more easilyseparated from the charge when subjected to oxidation reactions.Finally, selective oxidation of portions of an upgraded charge mayrender it more stable in storage.

One undesirable oxidation reaction is formation of excessive amounts ofnon-condensable gas that may have to be vented from the process vesselas discussed previously to control the impact of non-condensable gas onsaturated steam temperature. Heat generated in any oxidation reactionapproximately balances out energy loss due to venting thenon-condensables and accompanying steam vapor. Conversely, if morenon-condensable gas is desired in the process vessel, then air would bethe preferred source of oxygen for the oxidation reaction, because ofthe high nitrogen (a non-condensable gas) content of the air and thefact that any oxidation reactions involving oxygen in the air form anon-condensable combustion product.

The purpose of adding air or other gas containing reactive oxygen isbelieved fulfilled when about 0.00005 pounds of reactive oxygen perpound of upgraded charge (dry basis) to about 0.05 pounds of reactiveoxygen per pound of upgraded charge (dry basis) is added. About 0.00001to about 0.025 pounds of added reactive oxygen per pound of upgradedcharge (dry basis) is more preferable, with about 0.005-0.01 pounds ofadded reactive oxygen per pound of upgraded charge (dry basis) beingmost preferable.

FIG. 4A shows details of how the charge material within process vessel106 is separated from water expelled therefrom. Both moisture eliminatedfrom the charge material and steam condensate from the heating mediumhave to be continuously removed from vessel 106 as hot process water.This can be a difficult task, since both the charge material and the hotwater tend to flow downwardly through the process vessel 106 due togravity. Additionally, it is necessary to separate the two flows of thecharge and the moisture, such that essentially dry upgraded chargematerial is removed from process vessel 106 in one stream, and hot wateris removed in another totally separate stream or streams.

There are at least five different equipment arrangements usable forseparating hot water from the charge material moving downwardly throughprocess vessel 106. Examples are 1) outward sloping separation cone 402,2) vertical perforated drainage tubes 404 a, b, c, located in aninterior volume of process vessel 106, 3) vertical perforated drainagetube 406 located on a wall of vessel 106, 4) inward sloping separationcone 408, and 5) at least one rotatable horizontal separation table 410.

These various separation units can be used in a variety of combinationswith multiple placements within vessel 106 to effect the desired degreeof water/solid separation. Furthermore, although the view of openings inthe separation surface areas shows round holes 450 in FIG. 4B, theseopenings in the various separation areas alternatively could compriseslots, square openings, screens, grates, baskets, perforated tubes orany other device enabling hot water to pass through openings in theseparation device while blocking flow of the solid charge. The size ofthe openings is selected to ensure good drainage while minimizing escapeof fine solid materials. In addition, it is preferable to taper eachopening so that the opening on the water collection side is slightlylarger than the opening on the charge side. In this manner, solidparticles which may become lodged in the openings have a better chanceof being dislodged and passing through the opening.

Outward sloping separation cone 402 allows hot water to passsubstantially downwardly through separation openings in the surface ofcone 402, while the solid charge material is directed radially outwardlytoward the wall of process vessel 106. Hot water passing through theopenings in cone 402 is collected in a collection pan 412, or a headerserving a similar function, and hot water exits process vessel 106 viaan internal drain 414 which is coupled to hot water discharge 416.

As solid charge material is directed radially outwards, the materialflow can pass around and past internal drainage tubes such as 404 a, b,c which allow hot water to separate from the solid charge throughperforated holes in each tube. View A-A in FIG. 4D is a plan viewlooking down the interior volume of the process vessel 106 and showsthat the internal drainage tubes 404 can be arranged in concentriccircles which would provide multiple opportunities for hot water to beseparated from the solid charge. Collection headers at a bottom of eachtube collects the hot water and directs it to an internal drain 420which then allows hot water to discharge from process vessel 106 throughone or more hot water outlets 422.

Also shown in view A-A of FIG. 4D is an arrangement where the internalperforated tube 406 could be split in half and attached to a wall ofprocess vessel 106 in a circular array in water tight manner such thathot water can be removed from the charge material immediately adjacentthe vessel wall. Hot water collected in the tubes would be collected ina header at the bottom and passed out of the process vessel 106 as hotwater to discharge 418. A portion or all of the perforated tube arraycould be replaced by a concentric wall with separation openings securedto process vessel 106's wall at the top in a water tight manner and witha collection header at the bottom to collect and pass the hot water todischarge through at least outlets 418 and 422.

Part of the function of outwardly sloping separation cone 402 is todirect solid flow radially outward. Part of the function of the inwardlysloping separation cone 408 is to direct solid flow radially inwardly,while providing an opportunity for hot water to separate from the solidcharge material by flowing downwardly through openings in separationcone 408. View B-B of FIG. 4C looks downward on the inward slopingseparation cone 408 in plan view and shows that the cone is concentricand attached to an outer wall of process vessel 106. The cone extends inan arc through the entire circumference of process vessel 106. Cone 408could also be installed in segments and be discontinuous. Hot waterpassing through cone 408 openings 409 is collected in a concentricannular collection pan 424 which passes the hot water discharge throughat least one or more outlets in process vessel 106. Two outlets, 426 aand 426 b, are shown in FIG. 4A as an example.

With continued reference to FIG. 4A, separation devices 402, 404 a-c,406 and 408 could be installed in multiple locations such that solidcharge material flowing substantially downwardly in the process vessel106 would alternate in a radially outward flow to a radially inward flowpattern to provide multiple opportunities for charge solids to pass overor around surfaces of the separation devices.

View C-C in FIG. 4E is a downward looking plan view depicting asubstantially horizontal separation table 410 with perforated openings411 allowing hot water to pass downwardly, be collected in a collectionpan 428 and directed out of process vessel 106 through an internal drain430 in fluid communication with water discharge outlet 432. Althoughseparation table 410 is shown as a single table and as a complete circlein both plan and elevation views in FIGS. 4A and 4E, it would bepossible to use multiple concentric tables of increasing diameter, eachstacked underneath a smaller table above it such that solids would flowboth downwardly and outwardly while cascading from one table to thenext. Depending on placement and diameter of separation table or tables410, solid charge material will flow off an outer edge of each table dueto its angle of repose while the hot water will flow substantiallydownwardly through the table's perforations. Outward flow of chargesolids can be substantially improved if separation table 410 isrotatable. This will effectively lower the angle of repose of materialreferenced to horizontal and improve outward flow of such material. Itshould also be possible to position stationary plows or similarstructural members above rotating tables, such as 410, to improve theoutward flow of solids and direct the solid charge material outwardlyoff an edge of the table or tables.

Although not specifically shown in FIG. 4A, it would be possible toplace another inward sloping separation cone or concentric perforatedwall inside and above the lower discharge conical portion 434 of processvessel 106 to separate additional hot water from charge material justprior to the charge material's exit from process vessel 106 intodischarge lock hopper 108 (FIG. 3). It would also be possible to installany of the separation devices described above in discharge lock hopper108 to provide additional opportunity for separation of hot water fromupgraded charge material.

If the separation surfaces of the various separation devices of FIG. 4Awere solid instead of perforated, such surfaces would form internalchambers or tubes within process vessel 106. If each such chamber had aseparate inlet and outlet, then heating medium could be introduced intothe inlets, thermal energy transferred through the chamber or tube viaconduction, and thermal energy provided to process vessel 106 chargematerial in an indirect manner via the principles of conduction,convection and radiation heat transfer. Spent heating medium would thenbe conveyed out of the chambers or tubes through process vessel 106 tosupplement direct forms of energy that are introduced through heatingmedium inlets 314 and 316 (FIG. 3).

As a converse to putting energy into the process vessel 106, energycould also be removed from process vessel 106 as just described bysubstituting a cooling medium for a heating medium.

Referring again to FIG. 4A, if air or other suitable oxygen-containinggas is introduced into the process vessel 106 for purposes of thermallyoxidizing a portion of volatiles expelled from the charge, loweringrequired input energy, or for rendering the upgraded charge more stablein storage, it may be desired to premix the air or oxygen-containing gaswith the heating medium prior to introduction into process vessel 106through inlets 314 and 316. Although this may be the preferred approach,the air or oxygen-containing gas could also be introduced into processvessel 106 in any other inlet position. If premixed, the air oroxygen-containing gas would be substantially in an inert form and notcapable of reacting with the heating medium while in the piping leadingto, or in the heating medium inlets 314 and 316. Likewise, the air oroxygen-containing gas would be incapable of reacting with materials ofconstruction in the piping and inlets. Once in process vessel 106, theair or other oxygen-containing gas would be free to expand, mix andreact with various organic fuels present in the process vessel and serveits intended purpose. If the air or oxygen-containing gas were put intothe process vessel through a dedicated inlet, without inert heatingmedia being present, oxidation reactions could occur near to or withinthe inlet nozzle locations and damage the structural integrity thereofdue to excessive overheating from localized, highly exothermic oxidationreactions with the various organic based fuels being upgraded.

FIG. 5 is a schematic drawing showing a general equipment arrangement500 with input, internal, and output stream details for alternativeapproaches to rehydrating the upgraded charge material exiting processvessel 106 prior to storage and shipment. Two equipment configurationscan be used for rehydrating an upgraded charge in conduit 504. These areuse of equipment to provide a blender-mixer function 506 or equipmentfor rehydration 512, or both. The arrangement in FIG. 5 shows theblender-mixer 506 preceding the rehydration equipment 512, but thearrangement could also be reversed. Upgraded charge material in conduit504 as discharged from discharge lock hopper 108 of FIG. 3 may beunstable if the inherent moisture level in the material is excessivelylower than the equilibrium moisture level of the material. If this isthe case, rehydration moisture must be added back to the material toincrease the inherent moisture level to a safe differential limit belowthat of the material equilibrium moisture level.

One method of rehydrating an upgraded charge is to add wet partialupgraded or non-upgraded charge material in conduit 502 to upgradedcharge material in conduit 504, such that the blended mixture has adesired average inherent moisture content. The final blend must befairly homogenous, so appropriate equipment is required such as ablender or mixer 506. The blend could also be made on a belt conveyor orother conveying device, if the blending was complete and uniform.

One of the materials that could be used as wet partially upgraded ornon-upgraded charge material in conduit 502 is fines that exit processvessel 106 in the various hot water discharges. Another source of suchmaterial used in the blend could be feed charge material containing freesurface moisture, particularly fines that are screened out of thecarbonaceous material as described earlier to prepare a properly sizedfeed charge to process vessel 106.

If blending of solid charge materials to effect the desired degree ofrehydration is not sufficient, then water can be added directly toupgraded charge material in the form of vapor or liquid water in arehydration media input stream 510, for example via spray nozzles inequipment 512. The rehydration equipment 512 can be a moisturizingchamber, blender, mixer, or other device providing intimate and uniformcontact between the rehydration media in 510 and the feed chargematerial to the rehydration equipment in conduit 508, such that therehydrated upgraded charge material in conduit 514 contains the desiredamount of inherent moisture.

EXAMPLES

For each of the following examples, the total moisture in feed coal andthe inherent moisture in process coal are both measured by ASTM methodD3302, while equilibrium moisture is measured by ASTM method D1412-93.

Example 1

Run-Of-Mine (ROM) sub-bituminous coal from the Black Thunder Mine nearWright, Wyoming was sized at minus 1 1/2 inches by plus 16 mesh. Thesized coal had a moisture content of 25.2 weight percent (w %), anequilibrium moisture content of 24.5% w % and a higher heating value(HHV) of 9010 Btu per pound. The coal was thermally upgraded in abatch-type autoclave of about 4 liter interior volume. The autoclave wasa vertically oriented cylinder with about 1/16 inch mesh screenremovable basket in the top section into which about 350 grams of feedcoal is charged. The autoclave was sealed and saturated steam used toraise the pressure and corresponding saturated steam temperature to thetargeted test condition. As the steam condensed, heat was released andthe resultant condensate along with moisture released from the coaldrained and collected in the bottom of the autoclave, beneath the coalbasket. At the end of the targeted processing time, steam was vented outof the autoclave and the pressure lowered to ambient, at which time thebasket containing the thermally upgraded coal was removed and theprocessed coal submitted for analysis. Out of many tests that wereconducted, two serve to exhibit the impact of temperature on upgradedcoal properties. One was at a saturated steam temperature of 430° F. andthe other at 460° F., which corresponds to respective saturated steampressures of about 344 pounds per square inch absolute (psia) and 467psia. Gauge pressures at the elevation of the test facility are about12.5 psi lower than the absolute pressures stated. The processing timefrom start of steam addition to start of venting was about 52 minutesfor each test. When processed at 430° F., the upgraded coal had aninherent moisture level of 7.81 w %, an equilibrium moisture level of16.1 w % and a HHV of 11,397 Btu/lb. When processed at the highertemperature of 460° F., the upgraded coal had a lower inherent moisturelevel of 6.0 w %, a lower equilibrium moisture level of 14.1 w %, and aHHV of 11,674 Btu/lb. These two tests demonstrate the beneficial impactof increasing the processing temperature (and pressure), particularly interms of higher temperatures lowering the equilibrium moisture level inthe upgraded product.

Note: factors other than inherent moisture impact the HHV, such asvolatile content, ash content and sulfur content. Since different feedsamples were used in these examples, the relationship between inherentmoisture and HHV is not constant.

Example 2

The same type of feed coal used in Example 1 was tested at 17 minutestotal processing time at a temperature of 460° F., and when analyzed theinherent moisture level in the processed coal was still very low at 6.3w %, while the HHV was still relatively high at 11,598 Btu/lb, showingthat processing times less than 20 minutes still yield very acceptableresults comparable to processing times of 52 minutes. The effect ofprocessing time was further demonstrated using another sample of coalwith a starting inherent moisture level of 24.1 w %, which was processedat a temperature of 460° F. Processing times of 19, 32 and 52 minutesyielded respective inherent moisture levels in the upgraded product of8.8 w %, 8.4 w % and 8.7 w %, and while the final inherent moisturelevels were high as a group because of using a different sample of feedcoal, there was basically no difference in final moisture level amongthe three tests that can be attributed to processing time, at leastwithin the range of 19 to 52 minutes. Using a different batch autoclaveapparatus capable of processing about 10 pounds of coal per batch,another sample of the Black Thunder coal similar to that described inExample No. 1 was processed at 467° F. at over a very long time periodof 540 minutes. The inherent moisture level in the processed coal was6.2 w %, showing that excessively long processing time does not impactthe final moisture levels. Equilibrium moisture levels were not measuredin the samples processed at shorter and longer time periods compared tothe base cases at 52 minutes, but experience tells us that theequilibrium moisture levels are directly curvilinearly proportional tothe inherent moisture levels.

Example 3

In two different tests with the same type of feed coal described inExample 1, feed coal containing about 0.085 microgram per gram (μg/g)concentration of mercury, expressed on a dry basis, was tested where airwas added to one test and not to the other. With air addition, 72.1 w %of the mercury was removed from the processed coal and in the testwithout air addition, only 51.6 w % of the mercury was removed. Thisdemonstrates that air addition during processing improves mercuryremoval. The air addition was made at the start of the test, beforesteam was added, and did not flow continually into the batch autoclaveduring the tests, but it is recognized that the air could have beenadded on a semi-continuous or continuous basis as long as the autoclavewas vented to control the partial pressure of non-condensable gas withinthe autoclave as explained in the following discussion.

In these two tests, the temperatures were the same, but the pressureswere different. When air is added to the process, it occupies part ofthe total pressure with steam vapor occupying the other part. Forexample, if the total pressure in the processing vessel is 466 psia andair occupies 20 percent of the volume (v %) and steam the other 80 v %,the partial pressure of steam is only 373 psia, which corresponds to asaturated steam temperature of about 437° F., not 460° F. that would beexpected if the processing environment were 100 v % steam. As oxygen inthe air is consumed during processing due to oxidation reactions, thereaction products equal the volume of oxygen consumed, so there is nochange in temperature because of any change in steam partial pressure.The amount of air added during this particular test was about 0.06weight fraction per one unit of feed coal, keeping in mind that the airwas added on a batch basis at the beginning of the test. The samereasoning used to show the impact of air volume relative to steam volumeon steam temperature can also be expanded to explain the impact ofnon-condensable gas volume or concentration, as the oxygen and nitrogenin air are both non-condensable gases, as are oxidation products such ascarbon dioxide and carbon monoxide. Although carbon dioxide and carbonmonoxide are both non-condensable, only the oxygen in carbon monoxide isreactive under the processing conditions practiced in this invention.Other volatiles released from the charge during processing can also benon-condensable gases such as methane, propane, hydrogen sulfide, sulfurdioxide and etc.

Example 4

In another set of two different tests with the same type of feed coaldescribed in Example 1, air was added to one test on a continuous basisand was not added to the other test. As explained in Example 3, theprocess vessel was also vented on a continuous basis. Processingconditions were essentially equal in both tests with the same processingtemperatures and times. When the liquid collected in the two testsresulting from moisture released from the coal, steam condensate, andsoluble volatile organics was analyzed, the test with air addition had alower concentration of Total Organic Carbon in the liquid, about 278milligrams per liter (mg/l), than the test without air addition, orabout 620 mg/l, indicating that oxygen in the air was reacting with theorganics released from the coal either before, or while it was incontact with the water. This was also evident by less colorization inthe water from soluble organics in the test where air was added. Whenorganics are selectively oxidized while in the process vessel, theoverall beneficial impact is to lower the cost of water treatment andclean-up. The amount of air added during this particular test was about0.002 weight fraction per unit of unit of feed coal, keeping in mindthat it was added continuously over the length of the test.

Example 5

Referring back to Example 1, there are thermocouples in both the upperand lower sections of the autoclave. Since steam condenses isothermallyat the saturation temperature after the coal charge is heated up toprocessing temperature, one would expect both thermocouples to indicatethe same temperature as the thermal upgrading process continues, butthat is not the case. Based on volatile assay of the coal before andafter processing, 1 w % to 5 w % of the coal feed weight is lost asvolatiles, on a MAF basis (moisture and ash free). Of this amount,analysis of the non-condensable gas generated in the up-grading processbased on tests without air addition, indicates that about 95 v % of thevolatiles that are lost are carbon dioxide gas. In the autoclave tests,any non-condensable gas that is generated is not normally vented out ofthe process until the test is over. If the carbon dioxidenon-condensable gas was mixed uniformly with the steam vapor, we wouldexpect both thermocouples in the upper and lower portions of theautoclave to read the same temperature, but at a slightly lowertemperature than would be predicted by the saturated steam pressure (seeExample 3) if some non-condensable gas were present. In all autoclavetests where liquid is not removed from the bottom portion of theautoclave during the test, the bottom thermocouple initially indicatesthe same temperature as the top thermocouple, but as the test proceeds,the bottom thermocouple starts to drop in temperature and has reached atleast 35° F. lower temperature than the top thermocouple. Based onvolumetric measurements, it is known that when the lower thermocoupledrops in temperature it is still located in vapor space and not immersedin liquid, but is just slightly above the liquid layer. During one testit was decided to drain liquid out of the bottom section before the testwas over and immediately the bottom thermocouple reading increased tomatch the top thermocouple, and then started decreasing again until moreliquid was drained. This observation and procedure has been repeatedwithout fail a number of times, and with different processing equipmentarrangements. It is now realized that high molecular weight gases, suchas carbon monoxide with molecular weight (MW) 44 does not mix uniformlywith steam water vapor with MW 18, but instead stratifies in a lowerlayer. When the carbon dioxide layer concentrated as the testprogressed, the saturated steam temperature as measured by thethermocouple progressively lowered due to partial pressure decrease ofthe steam vapor concentration (see Example No. 3 for discussion onnon-condensable gas affecting the saturated steam temperature) as carbondioxide concentrated in a stratified layer just above the liquidinterface. When the liquid interface was lowered due to removal ofliquid, the carbon dioxide was not removed, but the layer level loweredand allowed the set position thermocouple to measure gas temperaturethat was substantially steam vapor rather than a mixed highconcentration carbon dioxide and steam vapor concentration. Specialprocedures must be employed in the processing equipment to insure thathigh molecular weight non-condensable gases are effectively removed fromthe process vessel. By reasoning, the converse also holds true fornon-condensable gases that are lower in molecular weight than steamvapor, such as hydrogen with MW 2.

Example 6

Coal was also thermally upgraded in a semi-continuously fed anddischarged process vessel consisting of about a 6 inch interior diameterby 60 inch high cylindrical pressure vessel orientated vertically,equipped with a feed lock hopper and a discharge lock hopper withappropriate lock hopper valves. The unit is fed about 12 lbs of feedcoal every 12-14 minutes which allows for a processing time of about 50to 55 minutes. The process vessel is also discharged about every 12-14minutes to maintain level control. Two tests point out the benefit ofadequate draining and dewatering of the upgraded charge before dischargefrom the process vessel. Black Thunder ROM coal sized at minus 1 inch byplus 8 mesh was used as the feed coal with a moisture content of 25.8%and a HHV of 9076 Btu/lb. Saturated steam at 459° F. and 462.5 psia wasused as the heating media. When liquid representing moisture removedfrom the coal plus steam condensate was continuously drained out of thebottom of the process vessel chamber and vented to atmosphere prior totransferring the upgraded-charge to the discharge lock hopper, theinherent moisture level in the upgraded coal when discharged was 5.0 w %with a HHV of 11,554 Btu/lb. When liquid was not properly drained out ofthe bottom of the process vessel chamber, and the upgraded coal wasallowed to be discharged with accompanying volumes of free liquid, theinherent moisture level in the upgraded charge was much higher at 12.6 w% with a HHV of 10,791 Btu/lb.

The invention has been described with reference to a detaileddescription only for the sake of example. The scope and spirit of theinvention are to be derived from the appropriately interpreted appendedclaims.

1. Apparatus for upgrading energy content of a charge of carbonaceousmaterial, the apparatus comprising: a process vessel having a chamberfor receipt of the charge, a carbonaceous material inlet fortransferring the charge to the chamber and a carbonaceous materialoutlet for transferring an upgraded charge out of the chamber; at leastone heating medium inlet adapted to be coupled to a source of a heatingmedium for transferring the heating medium under pressure into theprocess vessel chamber for direct contact with the charge; at least onefluid outlet; and at least one liquid separator having a liquid outletcoupled to the at least one fluid outlet and operative to separate thecharge from liquid and to pass separated liquid to the at least onefluid outlet.
 2. The apparatus of claim 1 wherein the heating mediumcomprises saturated steam.
 3. The apparatus of claim 1 wherein theheating medium comprises superheated steam.
 4. The apparatus of claim 1further comprising a plurality of heating medium inlets positioned at aplurality of positions along a length of the vessel.
 5. The apparatus ofclaim 1 further comprising a plurality of fluid outlets positioned at aplurality of positions along a length of the vessel.
 6. The apparatus ofclaim 1 further comprising a plurality of liquid separators positionedat a plurality of locations within the chamber.
 7. The apparatus ofclaim 1 wherein the at least one liquid separator comprises at least onerotating perforated table positioned in the vessel to direct liquidthrough perforations in the table to a liquid storage area coupled tothe liquid outlet and to direct charge material radially outwardlytoward a wall of the process vessel.
 8. The apparatus of claim 1 whereinthe at least one liquid separator comprises at least one perforated tubeextending along at least a portion of the chamber between an inlet andan outlet end thereof, a hollow interior of the at least one tubecoupled to the liquid storage area.
 9. The apparatus of claim 1 whereinthe at least one liquid separator comprises at least one perforated coneextending along a longitudinal axis of the chamber, having an apexpointing toward the vessel inlet and a base spaced from a chamber wall,a hollow interior of the at least one cone coupled to a liquid storagearea in turn coupled to the at least one liquid outlet.
 10. Theapparatus of claim 1 wherein the at least one liquid separator comprisesat least one truncated cone having a perforated wall extending from awall of the vessel toward the vessel output and terminating in anopening surrounding a longitudinal axis of the chamber, and an annularliquid storage area positioned between the perforated wall and thevessel wall.
 11. The apparatus of claim 1 further comprising: at leastone input lock hopper having an input adapted to receive carbonaceousmaterial and an output coupled to the carbonaceous material inlet; andat least one output lock hopper having an input coupled to thecarbonaceous material outlet and an outlet for delivering upgradedcarbonaceous material to a storage facility.
 12. The apparatus of claim1 further comprising: at least one gas inlet to the process vesselchamber adapted to be coupled to a source of gas containing reactiveoxygen.
 13. The apparatus of claim 1 wherein the at least one heatingmedium inlet is further adapted to be coupled to a source of gascontaining reactive oxygen.
 14. The apparatus of claim 1 furthercomprising at least one process vessel vent enabling selective dischargeof gases from the process vessel chamber.
 15. The apparatus of claim 1further comprising an indirect heat exchange element positioned at apreselected position within the process vessel chamber for indirectlyheating at least a portion of the charge.
 16. The apparatus of claim 1further comprising a rehydration system coupled to the carbonaceousmaterial outlet for receipt of upgraded charge and operative to add apreselected amount of moisture to the upgraded charge.
 17. Apparatus forupgrading energy content of a charge of carbonaceous material, theapparatus comprising: a substantially vertically oriented process vesselhaving a carbonaceous material inlet positioned at a top end of thevessel, a carbonaceous material outlet positioned at a bottom end of thevessel and a chamber for receipt of the charge extending from thecarbonaceous material inlet to the carbonaceous material outlet; aplurality of heating medium inlets adapted to be coupled to a source ofa heating medium for transferring the heating medium under pressure intothe process vessel chamber for direct contact with the charge, theheating medium inlets positioned at preselected locations between thetop end and the bottom end of the vessel; a plurality of liquid outletspositioned at preselected locations between the top end and the bottomend of the vessel; a plurality of process vessel vents for enablingselective discharge of gases from the process vessel chamber andpositioned at preselected locations between the top end and the bottomend of the vessel; and a plurality of liquid separators positioned at aplurality of preselected locations within the chamber, each liquidseparator having a liquid collection chamber coupled to at least one ofthe plurality of liquid outlets and operative to separate the chargefrom liquid and to pass separated liquid to the at least one of theplurality of liquid outlets.
 18. The apparatus of claim 17 wherein thelocations of the plurality of process vessel vents are preselected suchthat lighter-than-water vapor non-condensables generated in the processvessel chamber are removed from upper regions of the process vesselchamber and such that heavier-than-water vapor non-condensablesgenerated in the process chamber are removed from lower regions of theprocess vessel.
 19. The apparatus of claim 17 wherein the locations ofthe plurality of heating medium inlets are preselected such that chargematerial entering the carbonaceous material inlet is rapidly heated to apreselected vessel operating temperature and such that free moisture onsurfaces of charge material about to enter the carbonaceous materialoutlet is converted to vapor form.
 20. The apparatus of claim 17 whereinthe locations of the plurality of process vessel vents are on oppositesides of and substantially at a same height as locations ofcorresponding heating medium inlets whereby efficient flow of theheating medium throughout the process vessel chamber is promoted. 21.The apparatus of claim 17 further comprising a plurality of gas inletsto the process vessel chamber adapted to be coupled to a source of gascontaining reactive oxygen and positioned at a plurality of locationsalong the length of the vessel.
 22. The apparatus of claim 21 whereinthe plurality of locations of the gas inlets are in substantially samelocations of the plurality of heating medium inlets.
 23. The apparatusof claim 17 wherein the plurality of heating medium inlets are furtheradapted to be coupled to a source of gas containing reactive oxygen. 24.The apparatus of claim 17 wherein the plurality of liquid separatorscomprises: a first perforated conical surface positioned in an upperportion of the chamber and extending radially outwardly and downwardly,and a collection chamber beneath the first perforated conical surface influid communication with a first liquid outlet; at least one hollow tubehaving a perforated surface extending downwardly in the chamber beneaththe first perforated conical surface and having a lower end in fluidcommunication with a second liquid outlet; and a separation table havinga perforated surface in a lower portion of the chamber beneath the atleast one hollow tube and having a collection chamber beneath theperforated surface in fluid communication with a third liquid outlet.25. The apparatus of claim 17 further comprising a rehydration systemcoupled to the vessel outlet for receipt of upgraded charge andoperative to add a preselected amount of moisture to the upgradedcharge.
 26. A method for upgrading energy content of a charge ofcarbonaceous material having a first equilibrium moisture levelcomprising: directly contacting the charge with a heating medium underpressure to heat the charge to drive moisture from the charge to asecond moisture level below the first equilibrium moisture level and tolower an equilibrium moisture level of the charge to a value between thefirst equilibrium moisture level and the second moisture level; andseparating driven moisture from the charge.
 27. The method of claim 26further comprising: rehydrating the charge to a third moisture levelhigher than the second moisture level but less than the firstequilibrium moisture level of the charge.
 28. The method of claim 26wherein the heating medium comprises saturated steam.
 29. The method ofclaim 28 wherein the charge is heated to between a minimum temperaturewhere structure of charge particles become elastic and a maximumtemperature where pyrolysis occurs.
 30. The method of claim 29 whereinthe minimum temperature is about 400° F. and the maximum temperature isabout 500° F.
 31. The method of claim 30 wherein the charge is heatedunder pressures of between about 247 psia and about 680 psia.
 32. Themethod of claim 26 wherein the heating medium comprises superheatedsteam.
 33. The method of claim 28 wherein a portion of the heatingmedium comprises compressed hot water condensed from the saturatedsteam.
 34. The method of claim 32 wherein a portion of the heatingmedium comprises compressed hot water condensed from the superheatedsteam.
 35. The method of claim 26 wherein the charge is directlycontacted with the heating medium under pressure for a time period ofabout 5 minutes to about 1000 minutes.
 36. The method of claim 26wherein the charge is directly contacted with the heating medium underpressure for a time period of about 15 minutes to about 60 minutes. 37.The method of claim 26 wherein the charge is directly contacted with theheating medium under pressure for a time period of about 20 minutes toabout 30 minutes.
 38. The method of claim 26 wherein the second moisturelevel is between about 20% and about 60% of the first equilibriummoisture level.
 39. The method of claim 27 wherein the third moisturelevel is between about 101% and about 125% of the second moisture level.40. The method of claim 27 wherein the third moisture level is betweenabout 110% and about 120% of the second moisture level.
 41. The methodof claim 27 wherein rehydrating is carried out in a moisturizingchamber.
 42. The method of claim 27 wherein rehydrating is carried outby spraying the upgraded charge with water via at least one spraynozzle.
 43. The method of claim 27 wherein rehydrating is carried out byblending an upgraded charge with non-upgraded carbonaceous material. 44.The method of claim 26 further comprising: adding a gas containingreactive oxygen to the heating medium in an amount sufficient tothermally oxidize at least a portion of organic-based volatiles expelledfrom the charge.
 45. The method of claim 26 further comprising: adding agas containing reactive oxygen to the heating medium in an amountsufficient to create acceptable oxidation reactions thereby lowering arequired energy input to heat the charge.
 46. The method of claim 26further comprising: adding a gas containing reactive oxygen to theheating medium in an amount sufficient to cause passive oxidation ofreactive sites in the charge, thereby rendering an upgraded charge morestable in storage.
 47. The method of claim 26 further comprising addinga gas containing reactive oxygen to the heating medium in an amountbetween about 0.00005 pounds oxygen per pound of upgraded charge (drybasis) and about 0.05 pounds oxygen per pound of upgraded charge (drybasis).
 48. The method of claim 26 further comprising adding a gascontaining reactive oxygen to the heating medium in an amount betweenabout 0.00001 pounds oxygen per pound of upgraded charge (dry basis) andabout 0.025 pounds oxygen per pound of upgraded charge (dry basis). 49.The method of claim 26 further comprising adding a gas containingreactive oxygen to the heating medium in an amount between about 0.0005pounds oxygen per pound of upgraded charge (dry basis) and about 0.01pounds oxygen per pound of upgraded charge (dry basis).
 50. The methodof claim 26 further comprising adding a gas containing reactive oxygento the heating medium in an amount sufficient to cause mercury level inthe charge to decrease.
 51. The method of claim 26 further comprisingheating at least a portion of the charge via indirect heat exchange. 52.The method of claim 26 further comprising: sizing the charge prior todirect contact with the heating medium within preselected upper andlower size limits.
 53. The method of claim 52 wherein sizes of chargematerial are distributed within the upper and lower size limitsfollowing a Rosin-Rammler index for the charge material.
 54. The methodof claim 26 wherein the carbonaceous material comprises coal. 55.Carbonaceous material upgraded by the method of claim
 26. 56. The methodof claim 26 further comprising venting non-condensable gas while heatingthe charge so as to maintain uniform temperature conditions throughoutthe charge.
 57. The method of claim 56 wherein the venting is performedcontinuously while heating the charge.
 58. The method of claim 56wherein the venting is performed periodically while heating the charge.